Ophthalmic microscopes are well known in the art. An ophthalmoscope which includes a laser photocoagulator is disclosed in U.S. Pat. No. 4,669,873 granted to the present Applicant. Such ophthalmoscopes or ophthalmic microscopes are used to image the vitreous and retina of the eye, typically without the use of a contact lens. Illumination of the retina and vitreous is somewhat difficult due to the constraints of the relatively small sized pupil through which the vitreous and retina are viewed and also due to the fact that the vitreous does not allow light to pass freely through it without some scatter and absorption.
In U.S. Pat. No. 4,307,944 also granted to the present Applicant, a dual slit-lamp illumination system is disclosed which allows the fundus of the eye to be illuminated using the two slit beams.
It has been found that the prior art devices and the known methods of using the prior art devices do not yield scale correct image projection and do not provide good illumination which is easy to work with.